Breaker-tooth



(No Model.)

G. W. CROSS 8v E. J. TOUHILL.

BREAKER TOOTH.

No. 550.253. Patented Nov. 26, 1895.

UNITED STATES PATENT OFFICE.

GEORGE IV. CROSS AND-EDVVARD J. TOUHILL, OF PITTSTON, PENNSYLVANIA.

BREAKER-TOOTH.

SPECIFICATION forming part of Letters Patent No.,550,253, dated November 26, 1895. Application filed December 20, 1894. Serial No. 532,511. (No model.)

To all whom it concern:

Be it known that we, GEORGE IV. CROSS and EDWARD J. TOUHILL, of Pittston, in the county of Luzerne and State of Pennsylvania, have invented a certain new and useful Improvement in Breaker-Teeth, of which the following is a specification.

Our invention relates to an improvement in machinery for crushing or breaking coal, ore, and other material. It is designed for use more particularly in coal-breakers where, as is well known, the coal after being brought from the mine is crushed by suitable mechanism before being passed through the screens. This mechanism usually consists of a number of rolls provided with teeth. The coal passes between these rolls and is disintegrated and crushed to the desired extent by the teeth.

The main difficulty now experienced not only in coal-crushers, but also in ore and stone crushers, is that by reason of the abrasion of the coal upon the teeth of the rolls the latter are quickly blunted and worn down to such an extent that they fail to properly perform their office. NVhen this happens, it has been necessary to remove the rolls from the crushing apparatus, detach the teeth, and replace them with new ones. This requires a great deal of work and consumes much time, and frequently coal-breakers are provided with an extra set of rolls, so that when one set is removed, instead of waiting to have it repaired, the extra set may be placed in position. The process of removing the teeth of a roll is not only time-consuming, but it requires special machinery or appliances, and is therefore expensive. In the invention contemplated herein it is designed to obviate these difficulties by the employment in the rolls above mentioned of teeth provided with detachable heads, which shall not only more effectively crush the coal or other material, but shall be cheap in manufacture, durable in operation, and capable of being readily and quickly placed in position. It will of course be understood that the office of a breakertooth is performed chiefly by its head or point. The body of the tooth is subject to comparatively little wear, and will last many times longer than the head itself. It is therefore designed to construct the tooth in such a manner that the body of the tooth may be permanently secured to the roll and the head attached in such a manner as to preclude its being displaced inthe operation of the. apparatus and yet permit of its ready removal when worn out, so that it may, by a simple and quick operation, be replaced by anew and perfect head without removing the roll to which such tooth is attached.

A further object of the invention is to provide means for guarding against the'turning of the tooth. curved in the direction'of the roll. If these teeth should during the crushing operation turn so that the curve was in the reverse direction, obviously the operation would be less efficient. To this end the head of the tooth in the present case is so secured to the body that it cannot turn nor become displaced in any manner.

In the drawings, Figure 1 is a side view of a breaker-tooth, illustrating our invention. Fig. 2 is an end view thereof. Fig. 3 is a sectional view. Fig. 4 is a top View of the body of the tooth, and Fig. 5 is an under side view of the head or point of the tooth.

Referring to the drawings, in which similar letters of reference denote corresponding parts, A designates the body of the tooth. It may be rectangular or circular in cross-section, and is preferably provided with a downwardly-projecting shank a, which may, if desired, be tapering, by means of which it is driven into a perforation provided in the breaker-roll or other foundation for that purpose. In the drawings the tooth is illustrated as approximately elliptical in cross-section toward its upper end, the object of which is to present a narrow edge to the material being crushed.

The body A of the tooth is provided with a recess a in its upper end and a tubular perforation a extending therefrom into the interior of the body. As here shown, the perforation a is intercepted by a transverse recess a the purpose of whichwill be hereinafter described. The body is also provided with an elevation or raised portion a, which is designed to engage witha suitable recess in the head to prevent said head from turning.

B designates the head or point of the tooth. This preferably rises to a point at the extreme top I), while its base is, like the body A, ap-

In many cases the teeth are proximately elliptical in form, having four crushing edges b b b 12 The under side of the head is provided with a recess C, with which engages the raised portion a thus insuring the retention of the head in proper position..

G designates an approximately circular projection from the under side of the head of such dimensions as to engage with the recess a in the body A.

C designates a downwardly extending shank, preferably formed integral with the head, and of such dimensions as to fit closely within the perforations a Now as to the manner in which the head is secured to and detached from the body of the tooth. It will be understood that the body is secured to the roll or other foundation by means of the shank a, which is driven into the perforation in such roll by any suitable means. The head may be placed upon the body and the shank C of the head placed within the perforation a and forced downwardly therein until the projection O is within the recess a and the under side of the head rests upon the upper surface of the tooth. \Vhile in this position, the head is precluded from being displaced, as well as from turning under the crushing operation. lVhen the head becomes worn from attrition or other causes, a key may be inserted in the transverse recess a and a few strokes of a hammer will detach the head from the body to permit of its being replaced with a new head.

There are many advantages other than those enumerated above flowing out of the invention. For instance, in this art it is desirable to use a comparatively soft but tough iron for the body of the tooth to resist the strain where the tooth is secured to the roll, but this material would be unsuitable for the point or head of the tooth. By means of the present invention we are enabled to employ the tough steel for the body of the tooth, while for the head or point a harder and more durable material may be employed, the conditions of wear being difierent from those present in the case of the body of the tooth.

\Ve do not desire to limit ourselves to the cross-section of the tooth shown in the drawing, as it is obvious that this feature may be varied as desired. For general uses, however, we have found the approximately elliptical form with the edges as illustrated most efficient.

The invention is of course applicable to crushing apparatus in which the teeth are mounted upon foundations other than rolls.

What we claim is-' A tooth for breaking or crushing machines, comprising a body portion approximately elliptical in cross section, and a separable head or point, having four crushing edges, and provided upon its under side with a projection G and a shank or finger, said projection and said shank or finger being adapted to engage with a socket in the body portion, said body portion having an integral upward extension or projection co-operatin g with a recess in the under side of said head or point to retain the latter in position, substantially as described.

This specification signed and witnessed th 4th day of December, 1894.

GEORGE XV. CROSS. EDVARD J. TOUIIILL. \Vitnesses:

S. P. FENN, F. H. KYTE. 

